感潮分汊河道平均分流、分沙比确定方法探讨

在感潮河段，汊道分流、分沙比随涨落潮过程的变化而变化，进行全潮施测较为困难。基于镇扬河段和畅洲汊道、扬中河段太平洲汊道的两次全潮水文测验，探讨了汊道平均分流、分沙比的确定方法。结果表明：涨潮过程中，分流、分沙比变化主要受涨潮流影响，变幅较大，且在高高潮前约2 h，主汊涨潮分流比、分沙比达全潮最大；落潮期间，分流、分沙比变化主要受主、支汊河道阻力对比影响，变幅较小；落潮流对分汊河道河床演变产生主要影响，故可用落潮平均分流比来代表汊道平均分流比。研究结果可为感潮汊道分流比、分沙比测验提供技术支持。

Determination and discussion of average flow and sediment diversion ratio of tidal braided river reach

In the tidal reach, the flow and sediment diversion ratios in branch reach change with the flood-ebb fluctuations, so the full tidal hydrology observation is difficult. Based on two full tidal hydrology observations of Hechangzhou branch in Zhenyang reach and Taipingzhou branch in Yangzhong reach, the determination method of average flow and sediment diversion ratio is discussed. The results show that during flood tide, the flow and sediment diversion ratios are mainly influenced by the tide rising, and the diversion ratio changes greatly; the flow and sediment diversion ratios of main branch reach the largest about 2 hours before the high tide. During the ebb tide, the fluvial evolution process is dominated by the ebb tide, so the flow and sediment diversion ratios in branch reach can be expressed by the average diversion ratios in ebb tide.